Se difunde a través del estrecho espacio y se adhiere a los receptores, que son moléculas especiales de proteínas que se encuentran en la membrana postsináptica. Esta es la sinapsis química Esta es inhibitoria o exitatoria O entre una neurona y una célula efectora L s i p a n i s a s ¿Que es la sinapsis? Existen dos, química y eléctrica Química Mediante potencial de membrana de la membrana post sináptica. Las sinapsis que hacen entrar corriente a la neurona (y por ende acercan el potencial de membrana al potencial de disparo de -55 mVolts) se llaman sinapsis excitatorias. Las sinapsis que hacen bajar el potencial de membrana (es decir de -70 mV a -80 mV) o que lo fijan inamoviblemnete a -70 se llaman sinapsis inhibitorias. En términos sencillos podemos decir que ...mientras que las inhibitorias hacen todo lo contrario, esto quiere decir que modulan el potencial de la membrana en conjunto." Clasificación mediante potencial physicists discovered cosmological redshift of light. (which is an optical Doppler-effect.) they realized that stars out of our galaxy all suffer redshift, therefore they get further and further from us. light also travels in time. so if we look at the stars, we can only see the past. which states that at the very beginning, the whole universe was a single point, with extreme density and temperature, then it started to expand rapidly (like an explosion), and the expansion is still going on for at least 13 billion years. so they could model the Big Bang theory this was the state of singularity, where the number of dimensions are infinite. There was no space and no time. with Einstein's theory, scientists also discovered black holes the very heavy radio stars, whose gravitational field is so strong that even light can't escape from them. that's why they are 'invisible' The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole. but what is relativity? imagine that you're in an elevator with your friend what you see is that the world around you is moving but from an other point of view, you're the ones who actually move Following this logic we can easily admit that everything is relative. except the speed of light. The speed of light is a constant. Light consists of photons, the particles whose mass is 0. this is something that never changes. Nothing can reach the speed of light that is heavier than photons. Therefore the only things which can exceed the speed of light are things with negative mass. Es la unión del neurotransmisor al receptor, produce una hiper polarización de la membrana post-sináptica llamada potencial inhibitorio postsináptico, PIPS. El PIPS es igualmente un potencial graduado. interesting consequences DO YOU NOW SEE THE LIGHT? imagine your friend now flying with his spaceship and yourself watching him with your binoculars exactly when he's half-way between two twin stars, suddenly the stars explode in exactly the same time as you know, the light beams from both exploding stars travel with the same speed, and you see that they reach you at exactly the same time but what he sees from the inside, is quite different. as he travels towards the 2nd star, he actually reaches the beam from the 2nd star first. 1st 2nd From different reference frames, there can never be agreement on the simultaneity of events. so he will think that the 2nd star exploded first. who's right? Einstein tells us that both are correct, within their own frame of reference. This is a fundamental result of special relativity: so these are the miraculous rules of our universe we have all experienced the Doppler-effect: it's the phenomenon when an ambulance passes by you with its sirens turned on. The sound you hear when it approaches is different from the one when it departs. Los neurotransmisores modifican la permeabilidad de Cl- K+ Cl (Membrana) Recuerde que el potencial de membrana fluctúa alrededor de los -70 mVolts. ! "Hay impulsos sinápticos entre neuronas destinados a incrementar la probabilidad de que se produzca una descarga eléctrica por el axon de la neurona...